Enhanced layerwise model for laminates with imperfect interfaces – Part 1: Equations and theoretical validation

The aim of this paper is the enhancement and validation of a layerwise model applied to the analysis of laminates with thin layers of an elastic–plastic adhesive. The thin adhesive layers are modelled as imperfect interfaces across which displacement discontinuities exist. In a previous paper, the constitutive equations of the imperfect interfaces were empirically established without following the layerwise logic. The model equations are revisited and a solid theoretical justification of the new enhanced equations is obtained by making use of the Hellinger–Reissner functional. A theoretical validation of the model is performed by comparing its predictions to those of a solid finite element resolution in the case of a T-peel joint. The results of the enhanced version of the model are very accurate whereas those of the previous version are erratic for the considered joint. As compared to the solid finite element method, an important saving in computational cost is achieved.